In manner very similar to how smartphones revolutionized personal computing, unmanned aerial vehicles (“UAVs”) are poised to change our civilian society in ways that have yet to be imagined. While it is too early to predict all of the areas of life in which UAVs will have an impact, it appears all but certain that their widespread use is imminent.
One of the key technologies enabling autonomous (as opposed to piloted) use of UAVs is positioning and control. Conventionally, UAV designers have put emphasis on absolute positioning (the specific location or position of the UAV in a coordinate space), since it has generally been thought of as being instrumental to the success of the mid- to high-altitude intelligence, surveillance, and reconnaissance (“ISR”) missions where UAVs have typically been used by the military (the primary user of UAVs to date). With the proliferation of low-flying portable UAVs (e.g. multi-rotors), however, reliable relative positioning, independent of GPS, is crucial. This will enable UAVs to safely operate in close proximity to and relative to other (mobile) humans and machines, for both military and civilian applications.
The past five years have seen an explosion in consumer “drones”, with some as inexpensive as $300. As this technology matures (e.g., in terms of endurance for VTOL multi-copters), prices continue to decrease, and the regulatory environment opens their wider use, various types of UAVs will find numerous consumer, commercial, and governmental applications. Indeed, the use of personal UAVs—those that can be operated by a single user and function with a level of autonomy that enables their user to carry on his various tasks without having to dedicate much attention to the vehicle operation—are expected to increase dramatically in the coming years. Personal UAVs can be thought of as physical extensions of the user, and as such tightly follow their user motion—just as arms and legs move with the rest of one's body.
To ensure their widespread adoption, personal UAVs generally cannot require their user to become skilled remote control pilots. In addition, they should operate as autonomously as possible, in order to free the user to focus on the specific activity, instead of worrying about operating the UAV.
Before such personal UAVs can become a reality, therefore, they should generally be able to reliably and accurately follow their user regardless of the user's dynamics and regardless of the environment (GPS/no GPS, indoor/outdoor, open/urban, line-of-sight/non-line-of-sight) and of obstacles. The user can be a person (walking, running, biking, skiing, racing, etc.), an animal (military/search-and-rescue dog), another vehicle (a car, a truck, a piloted UAV, an unmanned UAV), or a stationary reference (landing pad or navigation beacon).
UAV positioning and control technologies have so far focused on performing these tasks in the absolute frame, i.e., with respect to global Earth coordinates. Exceptions do exist, especially for launch and recovery operations, but in such cases the technology used is either not suitable to mobile applications (e.g. landing radar) or the requirement it places on GPS availability makes it unsuitable to most urban and indoor applications. Developing such technology for personal UAVs independently of the availability of GPS will be the focus of our work.
The presently disclosed relative navigation system addresses many of the problems and issues set forth above, thereby enabling UAVs to be operated by personnel without piloting skill. As such, the presently disclosed system allows operators to simply designate where the UAV is to be positioned at all times by either embedding target device electronics in the object of interest, or by designating the desired location using a collimated light source. In addition, the presently disclosed system enables the UAV to automatically detect and avoid obstacles located within its path. Accordingly, the presently disclosed systems and methods for effectively and accurately navigating an unmanned aerial vehicle relative to a mobile target are directed to overcoming one or more of the problems set forth above and/or other problems in the art.